The 'Like a Virgin' singer, 61, who says she has been exposed to the virus, attended a friend's birthday party and was seen hugging and giving her friend Steven Klein a cake in celebration of his 55th birthday, the Mirror reports.

Madonna and Steven Klein in 2009. (Getty)

The singer appeared in a live stream which showed a group of performers putting on a show for attendees and viewers tuning in online. There was at least eight people visible in the virtual feed, The Daily Mail claimed.

The guests referred to the cake they'd presented Klein with as a "COVID cake", and were in close proximity throughout the duration of the celebrations.

"Took a test the other day, and I found out that I have the antibodies," Madonna said on May 1. "So tomorrow, I'm just going to go for a long drive in the car... and I'm going to breathe in the COVID-19 air. Yep. I hope the sun is shining."

The CDC is yet to confirm if the possession of antibodies means an individual is immune to the disease.

"That's the thing about COVID-19. It doesn't care about how rich you are, how famous you are, how funny you are.

"How smart you are, where you live, how old you are, what amazing stories you can tell. It's the great equaliser and what's terrible about is it what's great about it. What's terrible about it is that it's made us all equal in many ways and what's wonderful about is, is that it's made us all equal in many ways," she continued. "Like I used to say at the end of human nature every night, if the ship goes down, we're all going down together."

She deleted the video shortly after posting it when a major backlash ensued online.

Coronavirus: What you need to know

How can I protect myself and my family?

The World Health Organisation and NSW Health both recommend basic hygiene practices as the best way to protect yourself from coronavirus.

Good hygiene includes:

Clean your hands thoroughly for at least 20 seconds with soap and water, or an alcohol-based hand sanitiser;

Cover your nose and mouth when coughing and sneezing with tissue or your elbow;

Avoid close contact with anyone with cold or flu-like symptoms;

Apply safe food practices; and

Stay home if you are sick.

What is social distancing?

Social distancing involved minimising contact with people and maintaining a distance of over one metre between you and others.

When practicing social distancing, you should avoid public transport, limit non-essential travel, work from home and skip large gatherings.

It is okay to go outdoors. However, when you do leave home, avoid touching your face and frequently wash your hands.

If I'm young and healthy, do I still have to practice social distancing?

Yes. While older people are at higher risk of contracting COVID-19, young people are not immune. People that show mild or no symptoms may still pass the virus to others, particularly in the early stages of the infection, before many patients realise that they are sick.